QBurst Technologies Software Engineer Interview Questions and Answers

Implementing random function without in-built random()

• Use current time as seed value

• Generate a sequence of numbers using a mathematical formula

• Use external sources of randomness like atmospheric noise

• Implement a linear congruential generator

• Use a hash function to generate pseudo-random numbers

Merkle root is a hash value generated by hashing all the transactions in a block in a blockchain.

• Merkle root is used to efficiently verify the integrity of the transactions in a block.

• It is calculated by hashing the individual transactions in the block, then pairing and hashing those results until a single hash remains.

• Any change in the transactions will result in a different merkle root.

• Example: In a block containing transactions A, B, C, and D, the merkle root would be the ...read more

Prototype chaining is the mechanism in JavaScript where an object inherits properties and methods from another object.

• In JavaScript, each object has a prototype property which points to another object. When a property is accessed on an object, if it doesn't exist on the object itself, JavaScript looks for it in the prototype chain.

• If the property is not found in the immediate prototype, JavaScript continues to look up the chain until it finds the property or reaches the end o...read more

Promises in Node.js are objects representing the eventual completion or failure of an asynchronous operation.

• Promises are used to handle asynchronous operations in a more readable and manageable way.

• They can be in one of three states: pending, fulfilled, or rejected.

• Promises can be chained using .then() to handle success and .catch() to handle errors.

• Example: const myPromise = new Promise((resolve, reject) => { ... });

Temporal dead zone is the period between entering scope and being able to access a variable.

• Occurs when trying to access a variable before it has been declared

• Caused by hoisting in JavaScript

• Results in a ReferenceError

• Example: accessing a let or const variable before its declaration

Hardware refers to physical components of a computer, while RAM is a type of hardware that stores data temporarily.

• Hardware includes components such as the CPU, motherboard, and hard drive.

• RAM stands for Random Access Memory and is used to temporarily store data that the computer is currently using.

• Hardware is permanent and cannot be changed without physically replacing the component, while RAM can be upgraded or added to.

• Examples of hardware include a keyboard, mouse, and mo...read more